Mimosa pseudocallosa Burkart

Authors

Rupert C. Barneby

Authority

Barneby, Rupert C. 1991. Sensitivae Censitae. A description of the genus Mimosa Linnaeus (Mimosaceae) in the New World. Mem. New York Bot. Gard. 65: 1-835.

Family

Mimosaceae

Scientific Name

Mimosa pseudocallosa Burkart

Type

369. Mimosa pseudocallosa Burkart in Reitz, Fl. ilustr. catarin. LEGU(l): 215 + map, est. 34. 1979.—"Santa Catarina: Campo Alegre, Morro do Iquererim, beira de ragato, no campo, 1200 [m], . . . Reitz & Klein 6443 (05 02 1958)."—Holotypus, SI (not seen); i

Description

Species Description - Unarmed, functionally herbaceous subshrub from woody, adventitiously rooting branched caudex, the simple livid, bluntly ribbed, diffuse and incurved-ascending stems 3-5 dm, at anthesis defoliate proximally, distantly leafy distally, the whole plant appearing glabrous but the leaf-pulvini and dorsal face of pinna-rachises strigose with scattered subappressed setae and the corneous margin of plane subcoriaceous lfts appressed-setose-ciliolate, the globose capitula 1-3 in distal lf-axils on peduncle a little longer or shorter than subtending lf-stk. Stipules oblong-elliptic obtuse 2.5-6(-7) x 1-2.5 mm, coarsely (4-)5-6-nerved dorsally, glabrous or residually setose-ciliolate, tardily deciduous. Leaf-stalks 2-4.5 cm, proximally subterete but dorsiventrally compressed and to 0.7 mm wide distally, the terminal appendage subulate minute, spicule 0; pinnae 1-jug., the backwardly arched rachis 3-6 cm, the longer interfoliolar segments 1.5-2 mm; lfts of most pinnae 20-32-jug. (in some small early lvs fewer, no further described), the first pair ±1.5-2 mm distant from suborbicular, coarsely 3-5-nerved paraphyllidia 0.7-1.4 mm diam., the blades narrowly lance-oblong from broadly obtusangulate base, obtuse apiculate, the larger ones 6-10(-l 1.5) x 1.8-2.8(- 3) mm, all essentially nerveless above, beneath 3-nerved from pulvinule, the midrib slightly arched forward and displaced to divide blade ±1:2, the inner posterior nerve expiring near midblade, the outer posterior one much shorter, the marginal cilia free for 0.15-0.4 mm. Peduncles 20-27 mm; capitula without filaments 6-6.5 mm diam., prior to anthesis moriform, the prominently 4-angulate fl-buds glabrous; bracts linear- lanceolate ±1 mm, 1 -nerved; flowers 4-merous 4-androus, some lower ones staminate; calyx membranous 0.6-0.9 mm, the tube ±0.4 mm, the unequal subulate teeth 0.2-0.55 mm; corolla narrowly vase-shaped 2.7-2.8 mm, the ovate membranous, shallow-hooded but scarcely callous, strongly 1-nerved lobes ±1 x 0.6-0.7 mm; filaments pink, monadelphous through 0.7-0.9 mm, exserted 5-6.5 mm; ovary at anthesis glabrous; pod unknown.

Distribution and Ecology - On stream-banks in high campo, near 1300 m, known only from Morro do Iquererim in mun. Campo Alegre, far n.-e. Sta. Catarina, Brazil; to be sought in adj. Paraná.—Fl. II—III.

Discussion

Mimosa pseudocallosa is strongly differentiated by lack of prickles, extremely reduced indumentum, and dilated venulose paraphyllidia. Burkart associated it with members of subser. Reptantes of this revision, from which it differs technically by (inter alia) glabrous, not retrostrigulose corollas. In habit it recalls the ecologically comparable M. diffusa, but is of coarser growth, and differs in stipules, in foliose paraphyllidia, and deeply campanulate calyx. The epithet pseudocallosa draws attention to an odd similarity in foliage to some members of subser. Dolentes, but these are very different in form of inflorescence. At first I placed M. pseudocallosa only provisionally and with misgiving in subser. Sparsae, noting that its systematic position would need reassessment when the fruit became known, but the discovery in 1990 of M. prionopus has provided a plausible connection to subser. Sparsae. Its low stature and simply toothed, not paleaceous and fimbriate calyx separate it decisively, however, from M. prionopus.

Distribution

Brazil South America| Santa Catarina Brazil South America| Paraná Brazil South America|